A bent axis type axial piston motor in which a braking mechanism is disposed in a casing is already proposed. The braking mechanism is disposed in an accommodation space formed in the casing outer circumference of an end part of a drive shaft, and the braking mechanism includes a plurality of friction plates and a plurality of separate plates. Each of the friction plates and the separate plates is an annular thin flat plate, and the friction plates and the separate plates are alternately arranged in a manner such that separate plates are disposed on both sides of the arrangement. The friction plates are movable along an axis of the drive shaft and are restrained from rotating relative to the drive shaft, and the separate plates are movable along the axis of the drive shaft and are restrained from rotating relative to the casing.
A braking piston is disposed at a position facing a side of the alternate arrangement of the friction plates and the separate plates, and a brake force receiving member is disposed at a position facing the other side of the alternate arrangement. The braking piston is movable along the axis of the drive shaft, and in a normal state, the braking piston is pushed toward the separate plate by a braking spring disposed between the braking piston and the casing. If hydraulic pressure is applied to the braking piston from a hydraulic circuit (not illustrated), the braking piston is moved away from the separate plate against the pressing force of the braking spring. The brake force receiving member has an annular shape and is disposed in the accommodation space between the casing and the separate plate, and when the braking piston is pushed toward the separate plate, the brake force receiving member restricts movement of the fiction plates and the separate plates to generate friction forces between the friction plates and the separate plates.
In the above-described bent axis type axial piston motor, if a pressing force applied by the braking piston is removed, relative rotation between the friction plates and the separate plates is allowed, and thus the drive shaft can be rotated relative to the casing. On the other hand, if the friction plates and the separate plates are pushed to the brake force receiving member by the braking piston, relative rotation between the friction plates and the separate plates is restrained owing to friction forces acting therebetween, and thus the drive shaft is restrained from rotating relative to the casing (See, for example, Patent Literature 1).